The item order shouldnt be followed in just this order beacuse there might just be AD Champions in the opponents team so then you shouldnt by that many Armor items but if you dont want to run out Of mana buy Chailes Of Harmony and if you dont want to get hurt by jungle mods buy ninja tabis. In late game you maybe want to do norr damage you should sell Chailes of Harmony and buy Abyssal scepter beacuse then you Will do exactly 1% more Damage with despair.

Good luck and i hope you like My build.

Amumu is a great jungler and will need the blue buff in the begining. So start of at the Blue buff-->Wolf camp-->Ghosts-->Red buff--> Golem camp then you can chose between of going back to spawn or to gank in bot lane/top lane it depends on if you got enough health and if the opponents is pushing to your turret. If you desides to recall and then get back in lane you should try to steal the opponents blue buff and then gank top if they have push otherwise get back into you jungle and look for ganks while you jungle around and if your teammates need help just teleport up to them and help them. when you get Chalice of Harmony you wont need blue buff that much but if no one needs it go and take yourself. ooh i forgot dragon... you can solo it at level 8 and with teammates you can take it in level 4 and thats beacuse you doesnt have that much damage. but if you skip ranking up Bandage Toss and level Despair in level 4 and 5 you can solo it inn level 5.

In team fights you will be the initiater (initiate with Bandage Toss start cry(Despair) and use your Curse Of The Sad Mummy. this is a great suprise initiate if you have a fiddlestick,nunu,anivia,gangplank or a master yi(alpha strike) if you got one of these champions the other team will be destroyed.

if you like my build and you want to play 3v3 games with it, its perfect =) the only thing that you will need to change is the summoner spells (i like to use flash and clarity) and you should buy Cloth armor, 1 sight ward and 2 hp potions